Wear-reducing lubricating composition



3,001,937 Patented Sept. 26, 1961 3,001,937 WEAR-REDUCING LUBRICATING CDMPOSITION Albert G. Rocchini, Oakmont, and Charles E. Trautman,

Cheswick, Pa., assignors to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware No Drawing. Filed Oct. 17, 1958, Ser. No. 767,793 3 Claims. (Cl. 252-32) This invention relates to the lubrication of internal combustion engines, and more particularly to lubricatmg compositions having wear and corrosion reducing characteristics which suit them for use in the lubrication of internal combustion engines.

While the problem of combatting engine wear is important in the lubrication of all types of internal combustion engines the problem is particularly serious in the lubrication of low-speed marine diesel engines which operate on residual type fuel oils. It is known that residual fuel oils can be used to power low-speed marine diesel engines in lieu of the more costly lighter diesel fuels. Residual fuel oils of this type frequently contain sulfur and substantial amounts of vanadium and it has been recently observed that a large part of the wear occurring within the engine is attributable to the vanadium content of the fuel. The ash resulting from the combustion of the vanadium containing fuel is highly corrosive to engine parts such as cylinder walls, pistons, etc., which it contacts. The corrosive nature of the ash appears to be due to its vanadium oxide content.

It has now been found that wear occurring in internal combustion engines which operate on fuels containing vanadium in amounts sufficient to cause corrosion can be effectively minimized by the use of a lubricating oil having incorporated therein a vanadium-free organic manganese compound. The vanadium-free organic manganese compound is employed in the lubricating oil in small amounts sufficient to reduce corrosion by reaction of the manganese with the vanadium to form a non-corrosive ash. The organic manganese compounds are effective to reduce Wear when employed in the lubricating oil in relatively small amounts thus making the resulting lubricating compositions particularly advantageous for use in the lubrication of diesel engines and the Ike wherein the introduction of large amounts of metallic additives is to be avoided in order to prevent the metallic constituents of the additives themselves forming abrasive deposits within the engine. By having an organic compound of manganese present in the lubricating oil, it is available as a protective coating on metallic surfaces of the engine to react with the vanadium to render it non corrosive.

Lubricating compositions of the invention comprising a major amount of a lubricating oil and a minor amount of a vanadium free organic manganese compound are employed as lubricants in internal combustion engines which operate on fuels containing vanadium in amounts sufficient to cause corrosion. The new lubricants are particularly suited for the lubrication of low speed marine diesel engines which operate on high vanadium content fuels. The lubricating compositions of the invention can advantageously be employed as crankcase lubricants or upper cylinder lubricants in engines which employ separate cylinder lubrication.

The lubricating oil which constitutes the major ingredient of the new composition is selected from a wide variety of lubricating oils such as naphthenic base, paraffinic base and mixed base lubricating oils. In general, any mineral oil of lubricating viscosity or any synthetic lubricating oil such as polymerized olefins, polyalkylene oxides such as polypropylene oxide, polymerized glycols such as polyethylene glycol, organic esters such as di-Z- about 350 F. For the lubrication of low speed marine diesel engines a lubricating oil having a viscosity in the range of about 500 to 3000 Saybolt Universal seconds a 100 F. is generally employed.

Any organic compound of manganese which is free from vanadium can be used as the manganese additive in the lubricating compositions of the invention. These compounds include the oil-soluble and oil-dispersible salts of acidic organic compounds such as: (1) the fatty acids, e.g., valeric, caproic, Z-ethylhexanoic, oleic, palmitic, stearic, linoleic, tall oil, and the like; (2) alkylaryl sulfonic acids, e.g., oil-soluble petroleum'sulfonic acids and dodecylbenzene sulfonic acid; (3) long chain alkylsulfuric acids, e.g., lauryl sulfuric acids; (4) petroleum naphthenic acids; (5) rosin acids and hydrogenated rosin acids; (6) alkylpheno-ls e.g., iso-octylphenol, t-butylphenol and the like; (7) alkylphenol sulfides, e.g., bis(iso-octylphenol) monosulfide, bis(t-butylphenol) disulfide, and the like; (8) the acids obtained by the oxidation of petroleum waxes and other petroleum fractions; and (9) oil-soluble phenol-formaldehyde resins, e.g., the Amberols, such as t-butylphenol-formaldehyde resin, and the like. The salts or soaps of such acidic organic compounds as the fatty acids, naphthenic acids and rosins are relatively inexpensive and easily prepared and accordingly these are preferred materials for the organic additives.

The organic additives of the invention are oil-soluble or oil-dispersible and are therefore readily blended with the lubricating oils in the desired amount to form uniform blends. Since on a weight basis in relation to the oil, the amounts of the additives are small, it is desirable to prepare concentrated solutions or dispersions of the organic additives in a naphtha, kerosene or gas oil for convenience in compounding.

As has been stated, a sufficient amount of a compound of manganese is employed in a lubricating oil to confer improved wear reducing properties to the composition. Thus, the specific amounts to employ vary with the severity of the lubricating services required. -In general, the amount of the organic manganese additives to be employed depends: upon the vanadium content of the fuel and the rate of consumption of the fuel and lubricant. Thus, where the rate of consumption of the lubricant is relatively high with respect to fuel consumption as when the lubricating composition is employed as an upper cylinder lubricant and injected directly into the cylinders of the engine, relatively small amounts of the organic manganese compounds are employed. When the lubricating composition it is employed as a crankcase lubricant the rate of consumption of the lubricant is lower and accordingly larger amounts of the organic manganese compounds are employed. In each instance, the organic manganese compounds are employed in the lubricating oil in amounts suflicient to provide within the engine from about 0.01 atom weight to about 4 atom weights or more of manganese per atom weight of vanadium in the fuel consumed. The exact amount of the organic manganese compound to employ in the lubrieating oil can be readily determined from the vanadium content of the fuel and the respective rates of consumption of the fuel and lubricant.

The following examples further illustrate the invention which is not to be construed as limited thereby.

Example I 1640 grams of manganese naphthenate in petroleum naphtha solution (containing 6 percent manganese) is added to 14,760 grams of a mineral lubricating oil. The manganese naphthenate employed is a salt of a pctroleum naphthenic acid and is employed as a solution in a petroleum naphtha. A uniform blend was obtained by adding the manganese naphthenate with stirring to the oil at a temperature of 150200 F. The lubricating oil had the following inspection:

Copper strip test, 212 F., 3 hr l Neutralization value, ASTM D974:

Total acid No 0.03

The resulting lubricating oil composition had the following makeup:

Makeup: Percent by weight Oil base 90 Manganese naphthenate solution (6 percent manganese) 10 Example II Formulate a lubricating composition by blending 5 percent by weight of manganese naphthenate solution (containing 6 percent manganese) with 95 percent by weight of the above lubricating oil.

Example 111 Utilizing a mineral lubricating blend 1.5 percent by weight manganese sulfonate with 98.5 percent by weight of the lubricating oil.

Example IV Utilizing the same lubricating oil as in Example I blend 2.3 percent by weight of manganese tallate solution (containing 6 percent manganese) with 97.7 percent of the lubricating oil.

Example V Utilizing the same lubricating oil as in Example I blend 3.2 percent by weight of manganese tallate solution (containing 6 percent manganese) with 96.8 percent by weight of the oil.

Example VI Utilizing the same lubricating oil as in Example I blend 1.7 percent by weight of manganese tallate solution (containing 6 percent manganese) with 98.3 percent by weight of the oil.

Example VII Utilizing a lubricating oil comprising a di-Z-ethylhexyl sebacate blend 1.0 percent by weight of manganese naphthenate with 99 percent by weight of the lubricating oil.

Example VIII Utilizing a mineral lubricating oil blend 2.0 percent by weight manganese stearate with 98.0 percent by weight of the lubricating oil.

In order to test the effectiveness of the lubrication compositions of this invention in reducing wear, the lubricating compositions were employed as lubricants in an L-l single cylinder Caterpillar diesel engine having a bore of 5% inches and a stroke of 8 inches. The top ring of the diesel was activated to render it radioactive. The engine was flushed twice with portions of the test oil after which six quarts of test oil were placed in the crankcase and the engine started. A summary of the test conditions is as follows:

Water out 140 F.

Oil temperature 140 F. R.p.m. 825.

Horse power 15.

Oil pressure 30lbs./sq.in. Oil charge 6 quarts. Length of test 20 hours.

During the test the oil was continuously circulated through a well wherein a scintillation counter continuously recorded the radioactivity of the oil on a chart. The increase in redioactivity of the oil is utilized to indicate the degree of wear occurring within the engine by substituting into the following formula:

pounds of oi1 454 counts per gram of oil counts per milligram of iron in the standard In the above formula, the counts per milligram of iron in the standard is obtained by measuring the activity of an oil solution containing a weighed amount of a second iron ring which had been irradiated in the same manner as the test ring employed in the engine. The fuel employed in these tests was a residual type fuel oil having the following inspection:

Iron (milligrams) The following table shows the significant reduction in ring wear provided by representative lubricating compositions of the invention as compared with the base lubricating oil containing no additives.

Atom Weight Percent Ratio, Wear Be- Lubricant Mn:V duction over Base 011 Lubricating Composition of Example I.. 0 333:1 68 Lubricating Composition of Example II.-- 0. :1 41 Lubricating Composition of Example IV 0. 070:1 58 Lubricating Composition of Example V-.. 0. 105:1 79 Lubricating Composition of Example VL- 0.0561 60 1 Based on the vanadium content of the fuel and the amounts of the fuel and lubricant used.

As seen from the above data, the lubricating compositions of the invention significantly reduce wear in internal combustion engines operating on fuel containing vanadium in amounts suflicient to cause corrosion.

It is apparent also that small amounts of the manganese compounds are effective to reduce corrosion due to vanadium, thus making unnecessary the introduction into the engine of excessive amounts of manganese such as to result in the manganese itself forming large amounts of abrasive deposits.

The lubricating oil compositions of the invention are particularly suited forthe lubrication of diesel engines which operate on high vanadium content fuels. Furthermore the new compositions may advantageously be utilized in the lubrication of all types of internal combustion engines which operate on fuels containing vanadium in amounts sufiicient to cause corrosion.

In addition to the additives disclosed herein, there may be present in the lubricating compositions of this invention, other conventional additives such as antioxidants, pour point depressants, anti-rust agents, oiliness improvers, viscosity index improvers, detergents, dispersants, and the like.

Those modifications and equivalents which fall within the spirit of the invention and the scope of the appended claims are to be considered part of the invention.

We claim:

1. A method of reducing wear in diesel engines operating on fuels containing vanadium in amount suflicient to produce a corrosive ash upon combustion thereof which method comprises introducing into said engine as a lubricant a composition comprising a uniform blend of a major amount of a lubricating oil and a minor amount of a vanadium-free organic manganese compound sufiicient to reduce corrosion by reaction of the manganese compound with the vanadium to form a noncorrosive ash.

6 2. The method of claim 1 wherein the said lubricating composition is introduced into the crankcase of said diesel engine.

3. The method of claim 1 wherein the said composition is introduced directly into the cylinders of said 1 engine.

References Cited in the file of this patent UNITED STATES PATENTS 2,001,108 Parker May 14, 1935 2,228,500 Bergstrom Jan. 14, 1941 2,356,340 Murphree Aug. 22, 1944 2,367,470 Neely et a1. Jan. 16, 1945 2,379,241 McNab et al. June 26, 1945 2,560,542 Bartleson et a1. July 17, 1951 2,567,023 Morway et a1. Sept. 4, 1951 FOREIGN PATENTS 478,273 Great Britain Jan. 17, 1938 

1. A METHOD OF REDUCING WEAR IN DIESEL ENGINES OPERATING ON FUELS CONTAINING VANADIUM IN AMOUNT SUFFICIENT TO PRODUCE A CORROSIVE ASH UPON COMBUSTION THEREOF WHICH METHOD COMPRISES INTRODUCING INTO SAID ENGINE AS A LUBRICANT A COMPOSITION COMPRISING A UNIFORM BLEND OF A MAJOR AMOUNT OF A LUBRICATING OIL AND A MINOR AMOUNT OF A VANADIUM-FREE ORGANIC MANGANESE COMPOUND SUFFICIENT TO REDUCE CORROSION BY REACTION OF THE MANGANESE COMPOUND WITH THE VANADIUM TO FORM A NONCORROSIVE ASH. 